A New Species of Trichomycterus (Siluriformes: Trichomycteridae) from Madidi National Park, Amazon Basin, Bolivia

Abstract

Trichomycterus lauzannii, new species, is described from the upper Río Beni basin in La Paz, Bolivia. The new species is distinguished from congeners by the posterior cranial fontanel reduced to a small round opening on the posterior portion of supraoccipital bone and the possession of a rounded anterior cranial fontanel between frontal bones. In addition, the new species can be further distinguished from congeners by the possession of seven or fewer odontodes in the opercular patch, a pelvic fin which does not reach the anus when depressed, round blotches along the side of body, a first pectoral-fin ray prolonged as a short distal filament, and several meristic and morphometric features. Comparisons are given with similar congeners (T. cachiraensis, T. megantoni, T. sketi, and T. steindachneri).